// Copyright 2011 Baptiste Lepilleur and The JsonCpp Authors
// Distributed under MIT license, or public domain if desired and
// recognized in your jurisdiction.
// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE

#if !defined(JSON_IS_AMALGAMATION)

#include <utils/json/json_tool.h>
#include <utils/json/writer.h>

#endif // if !defined(JSON_IS_AMALGAMATION)

#include <algorithm>
#include <cassert>
#include <cctype>
#include <cstring>
#include <iomanip>
#include <memory>
#include <set>
#include <sstream>
#include <utility>

#if __cplusplus >= 201103L

#include <cmath>
#include <cstdio>

#if !defined(isnan)
#define isnan std::isnan
#endif

#if !defined(isfinite)
#define isfinite std::isfinite
#endif

#else

#include <cmath>
#include <cstdio>

#if defined(_MSC_VER)
#if !defined(isnan)
#include <float.h>
#define isnan _isnan
#endif

#if !defined(isfinite)
#include <float.h>
#define isfinite _finite
#endif

#if !defined(_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES)
#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 1
#endif //_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES

#endif //_MSC_VER

#if defined(__sun) && defined(__SVR4) // Solaris
#if !defined(isfinite)
#include <ieeefp.h>
#define isfinite finite
#endif
#endif

#if defined(__hpux)
#if !defined(isfinite)
#if defined(__ia64) && !defined(finite)
#define isfinite(x)                                                            \
  ((sizeof(x) == sizeof(float) ? _Isfinitef(x) : _IsFinite(x)))
#endif
#endif
#endif

#if !defined(isnan)
// IEEE standard states that NaN values will not compare to themselves
#define isnan(x) ((x) != (x))
#endif

#if !defined(__APPLE__)
#if !defined(isfinite)
#define isfinite finite
#endif
#endif
#endif

#if defined(_MSC_VER)
// Disable warning about strdup being deprecated.
#pragma warning(disable : 4996)
#endif

namespace Json {

#if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
    using StreamWriterPtr = std::unique_ptr<StreamWriter>;
#else
    using StreamWriterPtr = std::auto_ptr<StreamWriter>;
#endif

    String valueToString(LargestInt value) {
        UIntToStringBuffer buffer;
        char* current = buffer + sizeof(buffer);
        if (value == Value::minLargestInt) {
            uintToString(LargestUInt(Value::maxLargestInt) + 1, current);
            *--current = '-';
        } else if (value < 0) {
            uintToString(LargestUInt(-value), current);
            *--current = '-';
        } else {
            uintToString(LargestUInt(value), current);
        }
        assert(current >= buffer);
        return current;
    }

    String valueToString(LargestUInt value) {
        UIntToStringBuffer buffer;
        char* current = buffer + sizeof(buffer);
        uintToString(value, current);
        assert(current >= buffer);
        return current;
    }

#if defined(JSON_HAS_INT64)

    String valueToString(Int value) { return valueToString(LargestInt(value)); }

    String valueToString(UInt value) { return valueToString(LargestUInt(value)); }

#endif // # if defined(JSON_HAS_INT64)

    namespace {
        String valueToString(double value, bool useSpecialFloats,
                             unsigned int precision, PrecisionType precisionType) {
            // Print into the buffer. We need not request the alternative representation
            // that always has a decimal point because JSON doesn't distinguish the
            // concepts of reals and integers.
            if (!isfinite(value)) {
                static const char* const reps[2][3] = {{"NaN",  "-Infinity", "Infinity"},
                                                       {"null", "-1e+9999",  "1e+9999"}};
                return reps[useSpecialFloats ? 0 : 1]
                [isnan(value) ? 0 : (value < 0) ? 1 : 2];
            }

            String buffer(size_t(36), '\0');
            while (true) {
                int len = jsoncpp_snprintf(
                        &*buffer.begin(), buffer.size(),
                        (precisionType == PrecisionType::significantDigits) ? "%.*g" : "%.*f",
                        precision, value);
                assert(len >= 0);
                auto wouldPrint = static_cast<size_t>(len);
                if (wouldPrint >= buffer.size()) {
                    buffer.resize(wouldPrint + 1);
                    continue;
                }
                buffer.resize(wouldPrint);
                break;
            }

            buffer.erase(fixNumericLocale(buffer.begin(), buffer.end()), buffer.end());

            // try to ensure we preserve the fact that this was given to us as a double on
            // input
            if (buffer.find('.') == buffer.npos && buffer.find('e') == buffer.npos) {
                buffer += ".0";
            }

            // strip the zero padding from the right
            if (precisionType == PrecisionType::decimalPlaces) {
                buffer.erase(fixZerosInTheEnd(buffer.begin(), buffer.end(), precision),
                             buffer.end());
            }

            return buffer;
        }
    } // namespace

    String valueToString(double value, unsigned int precision,
                         PrecisionType precisionType) {
        return valueToString(value, false, precision, precisionType);
    }

    String valueToString(bool value) { return value ? "true" : "false"; }

    static bool doesAnyCharRequireEscaping(char const* s, size_t n) {
        assert(s || !n);

        return std::any_of(s, s + n, [](unsigned char c) {
            return c == '\\' || c == '"' || c < 0x20 || c > 0x7F;
        });
    }

    static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
        const unsigned int REPLACEMENT_CHARACTER = 0xFFFD;

        unsigned int firstByte = static_cast<unsigned char>(*s);

        if (firstByte < 0x80)
            return firstByte;

        if (firstByte < 0xE0) {
            if (e - s < 2)
                return REPLACEMENT_CHARACTER;

            unsigned int calculated =
                    ((firstByte & 0x1F) << 6) | (static_cast<unsigned int>(s[1]) & 0x3F);
            s += 1;
            // oversized encoded characters are invalid
            return calculated < 0x80 ? REPLACEMENT_CHARACTER : calculated;
        }

        if (firstByte < 0xF0) {
            if (e - s < 3)
                return REPLACEMENT_CHARACTER;

            unsigned int calculated = ((firstByte & 0x0F) << 12) |
                                      ((static_cast<unsigned int>(s[1]) & 0x3F) << 6) |
                                      (static_cast<unsigned int>(s[2]) & 0x3F);
            s += 2;
            // surrogates aren't valid codepoints itself
            // shouldn't be UTF-8 encoded
            if (calculated >= 0xD800 && calculated <= 0xDFFF)
                return REPLACEMENT_CHARACTER;
            // oversized encoded characters are invalid
            return calculated < 0x800 ? REPLACEMENT_CHARACTER : calculated;
        }

        if (firstByte < 0xF8) {
            if (e - s < 4)
                return REPLACEMENT_CHARACTER;

            unsigned int calculated = ((firstByte & 0x07) << 18) |
                                      ((static_cast<unsigned int>(s[1]) & 0x3F) << 12) |
                                      ((static_cast<unsigned int>(s[2]) & 0x3F) << 6) |
                                      (static_cast<unsigned int>(s[3]) & 0x3F);
            s += 3;
            // oversized encoded characters are invalid
            return calculated < 0x10000 ? REPLACEMENT_CHARACTER : calculated;
        }

        return REPLACEMENT_CHARACTER;
    }

    static const char hex2[] = "000102030405060708090a0b0c0d0e0f"
                               "101112131415161718191a1b1c1d1e1f"
                               "202122232425262728292a2b2c2d2e2f"
                               "303132333435363738393a3b3c3d3e3f"
                               "404142434445464748494a4b4c4d4e4f"
                               "505152535455565758595a5b5c5d5e5f"
                               "606162636465666768696a6b6c6d6e6f"
                               "707172737475767778797a7b7c7d7e7f"
                               "808182838485868788898a8b8c8d8e8f"
                               "909192939495969798999a9b9c9d9e9f"
                               "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
                               "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
                               "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
                               "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
                               "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
                               "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";

    static String toHex16Bit(unsigned int x) {
        const unsigned int hi = (x >> 8) & 0xff;
        const unsigned int lo = x & 0xff;
        String result(4, ' ');
        result[0] = hex2[2 * hi];
        result[1] = hex2[2 * hi + 1];
        result[2] = hex2[2 * lo];
        result[3] = hex2[2 * lo + 1];
        return result;
    }

    static void appendRaw(String& result, unsigned ch) {
        result += static_cast<char>(ch);
    }

    static void appendHex(String& result, unsigned ch) {
        result.append("\\u").append(toHex16Bit(ch));
    }

    static String valueToQuotedStringN(const char* value, size_t length, bool emitUTF8 = false) {
        if (value == nullptr)
            return "";

        if (!doesAnyCharRequireEscaping(value, length))
            return String("\"") + value + "\"";
        // We have to walk value and escape any special characters.
        // Appending to String is not efficient, but this should be rare.
        // (Note: forward slashes are *not* rare, but I am not escaping them.)
        String::size_type maxsize = length * 2 + 3; // allescaped+quotes+NULL
        String result;
        result.reserve(maxsize); // to avoid lots of mallocs
        result += "\"";
        char const* end = value + length;
        for (const char* c = value; c != end; ++c) {
            switch (*c) {
                case '\"':
                    result += "\\\"";
                    break;
                case '\\':
                    result += "\\\\";
                    break;
                case '\b':
                    result += "\\b";
                    break;
                case '\f':
                    result += "\\f";
                    break;
                case '\n':
                    result += "\\n";
                    break;
                case '\r':
                    result += "\\r";
                    break;
                case '\t':
                    result += "\\t";
                    break;
                    // case '/':
                    // Even though \/ is considered a legal escape in JSON, a bare
                    // slash is also legal, so I see no reason to escape it.
                    // (I hope I am not misunderstanding something.)
                    // blep notes: actually escaping \/ may be useful in javascript to avoid </
                    // sequence.
                    // Should add a flag to allow this compatibility mode and prevent this
                    // sequence from occurring.
                default: {
                    if (emitUTF8) {
                        unsigned codepoint = static_cast<unsigned char>(*c);
                        if (codepoint < 0x20) {
                            appendHex(result, codepoint);
                        } else {
                            appendRaw(result, codepoint);
                        }
                    } else {
                        unsigned codepoint = utf8ToCodepoint(c, end); // modifies `c`
                        if (codepoint < 0x20) {
                            appendHex(result, codepoint);
                        } else if (codepoint < 0x80) {
                            appendRaw(result, codepoint);
                        } else if (codepoint < 0x10000) {
                            // Basic Multilingual Plane
                            appendHex(result, codepoint);
                        } else {
                            // Extended Unicode. Encode 20 bits as a surrogate pair.
                            codepoint -= 0x10000;
                            appendHex(result, 0xd800 + ((codepoint >> 10) & 0x3ff));
                            appendHex(result, 0xdc00 + (codepoint & 0x3ff));
                        }
                    }
                }
                    break;
            }
        }
        result += "\"";
        return result;
    }

    String valueToQuotedString(const char* value) {
        return valueToQuotedStringN(value, strlen(value));
    }

// Class Writer
// //////////////////////////////////////////////////////////////////
    Writer::~Writer() =
    default;

// Class FastWriter
// //////////////////////////////////////////////////////////////////

    FastWriter::FastWriter()

    =
    default;

    void FastWriter::enableYAMLCompatibility() { yamlCompatibilityEnabled_ = true; }

    void FastWriter::dropNullPlaceholders() { dropNullPlaceholders_ = true; }

    void FastWriter::omitEndingLineFeed() { omitEndingLineFeed_ = true; }

    String FastWriter::write(const Value& root) {
        document_.clear();
        writeValue(root);
        if (!omitEndingLineFeed_)
            document_ += '\n';
        return document_;
    }

    void FastWriter::writeValue(const Value& value) {
        switch (value.type()) {
            case nullValue:
                if (!dropNullPlaceholders_)
                    document_ += "null";
                break;
            case intValue:
                document_ += valueToString(value.asLargestInt());
                break;
            case uintValue:
                document_ += valueToString(value.asLargestUInt());
                break;
            case realValue:
                document_ += valueToString(value.asDouble());
                break;
            case stringValue: {
                // Is NULL possible for value.string_? No.
                char const* str;
                char const* end;
                bool ok = value.getString(&str, &end);
                if (ok)
                    document_ += valueToQuotedStringN(str, static_cast<size_t>(end - str));
                break;
            }
            case booleanValue:
                document_ += valueToString(value.asBool());
                break;
            case arrayValue: {
                document_ += '[';
                ArrayIndex size = value.size();
                for (ArrayIndex index = 0; index < size; ++index) {
                    if (index > 0)
                        document_ += ',';
                    writeValue(value[index]);
                }
                document_ += ']';
            }
                break;
            case objectValue: {
                Value::Members members(value.getMemberNames());
                document_ += '{';
                for (auto it = members.begin(); it != members.end(); ++it) {
                    const String& name = *it;
                    if (it != members.begin())
                        document_ += ',';
                    document_ += valueToQuotedStringN(name.data(), name.length());
                    document_ += yamlCompatibilityEnabled_ ? ": " : ":";
                    writeValue(value[name]);
                }
                document_ += '}';
            }
                break;
        }
    }

// Class StyledWriter
// //////////////////////////////////////////////////////////////////

    StyledWriter::StyledWriter() =
    default;

    String StyledWriter::write(const Value& root) {
        document_.clear();
        addChildValues_ = false;
        indentString_.clear();
        writeCommentBeforeValue(root);
        writeValue(root);
        writeCommentAfterValueOnSameLine(root);
        document_ += '\n';
        return document_;
    }

    void StyledWriter::writeValue(const Value& value) {
        switch (value.type()) {
            case nullValue:
                pushValue("null");
                break;
            case intValue:
                pushValue(valueToString(value.asLargestInt()));
                break;
            case uintValue:
                pushValue(valueToString(value.asLargestUInt()));
                break;
            case realValue:
                pushValue(valueToString(value.asDouble()));
                break;
            case stringValue: {
                // Is NULL possible for value.string_? No.
                char const* str;
                char const* end;
                bool ok = value.getString(&str, &end);
                if (ok)
                    pushValue(valueToQuotedStringN(str, static_cast<size_t>(end - str)));
                else
                    pushValue("");
                break;
            }
            case booleanValue:
                pushValue(valueToString(value.asBool()));
                break;
            case arrayValue:
                writeArrayValue(value);
                break;
            case objectValue: {
                Value::Members members(value.getMemberNames());
                if (members.empty())
                    pushValue("{}");
                else {
                    writeWithIndent("{");
                    indent();
                    auto it = members.begin();
                    for (;;) {
                        const String& name = *it;
                        const Value& childValue = value[name];
                        writeCommentBeforeValue(childValue);
                        writeWithIndent(valueToQuotedString(name.c_str()));
                        document_ += " : ";
                        writeValue(childValue);
                        if (++it == members.end()) {
                            writeCommentAfterValueOnSameLine(childValue);
                            break;
                        }
                        document_ += ',';
                        writeCommentAfterValueOnSameLine(childValue);
                    }
                    unindent();
                    writeWithIndent("}");
                }
            }
                break;
        }
    }

    void StyledWriter::writeArrayValue(const Value& value) {
        size_t size = value.size();
        if (size == 0)
            pushValue("[]");
        else {
            bool isArrayMultiLine = isMultilineArray(value);
            if (isArrayMultiLine) {
                writeWithIndent("[");
                indent();
                bool hasChildValue = !childValues_.empty();
                ArrayIndex index = 0;
                for (;;) {
                    const Value& childValue = value[index];
                    writeCommentBeforeValue(childValue);
                    if (hasChildValue)
                        writeWithIndent(childValues_[index]);
                    else {
                        writeIndent();
                        writeValue(childValue);
                    }
                    if (++index == size) {
                        writeCommentAfterValueOnSameLine(childValue);
                        break;
                    }
                    document_ += ',';
                    writeCommentAfterValueOnSameLine(childValue);
                }
                unindent();
                writeWithIndent("]");
            } else // output on a single line
            {
                assert(childValues_.size() == size);
                document_ += "[ ";
                for (size_t index = 0; index < size; ++index) {
                    if (index > 0)
                        document_ += ", ";
                    document_ += childValues_[index];
                }
                document_ += " ]";
            }
        }
    }

    bool StyledWriter::isMultilineArray(const Value& value) {
        ArrayIndex const size = value.size();
        bool isMultiLine = size * 3 >= rightMargin_;
        childValues_.clear();
        for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
            const Value& childValue = value[index];
            isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
                           !childValue.empty());
        }
        if (!isMultiLine) // check if line length > max line length
        {
            childValues_.reserve(size);
            addChildValues_ = true;
            ArrayIndex lineLength = 4 + (size - 1) * 2; // '[ ' + ', '*n + ' ]'
            for (ArrayIndex index = 0; index < size; ++index) {
                if (hasCommentForValue(value[index])) {
                    isMultiLine = true;
                }
                writeValue(value[index]);
                lineLength += static_cast<ArrayIndex>(childValues_[index].length());
            }
            addChildValues_ = false;
            isMultiLine = isMultiLine || lineLength >= rightMargin_;
        }
        return isMultiLine;
    }

    void StyledWriter::pushValue(const String& value) {
        if (addChildValues_)
            childValues_.push_back(value);
        else
            document_ += value;
    }

    void StyledWriter::writeIndent() {
        if (!document_.empty()) {
            char last = document_[document_.length() - 1];
            if (last == ' ') // already indented
                return;
            if (last != '\n') // Comments may add new-line
                document_ += '\n';
        }
        document_ += indentString_;
    }

    void StyledWriter::writeWithIndent(const String& value) {
        writeIndent();
        document_ += value;
    }

    void StyledWriter::indent() { indentString_ += String(indentSize_, ' '); }

    void StyledWriter::unindent() {
        assert(indentString_.size() >= indentSize_);
        indentString_.resize(indentString_.size() - indentSize_);
    }

    void StyledWriter::writeCommentBeforeValue(const Value& root) {
        if (!root.hasComment(commentBefore))
            return;

        document_ += '\n';
        writeIndent();
        const String& comment = root.getComment(commentBefore);
        String::const_iterator iter = comment.begin();
        while (iter != comment.end()) {
            document_ += *iter;
            if (*iter == '\n' && ((iter + 1) != comment.end() && *(iter + 1) == '/'))
                writeIndent();
            ++iter;
        }

        // Comments are stripped of trailing newlines, so add one here
        document_ += '\n';
    }

    void StyledWriter::writeCommentAfterValueOnSameLine(const Value& root) {
        if (root.hasComment(commentAfterOnSameLine))
            document_ += " " + root.getComment(commentAfterOnSameLine);

        if (root.hasComment(commentAfter)) {
            document_ += '\n';
            document_ += root.getComment(commentAfter);
            document_ += '\n';
        }
    }

    bool StyledWriter::hasCommentForValue(const Value& value) {
        return value.hasComment(commentBefore) ||
               value.hasComment(commentAfterOnSameLine) ||
               value.hasComment(commentAfter);
    }

// Class StyledStreamWriter
// //////////////////////////////////////////////////////////////////

    StyledStreamWriter::StyledStreamWriter(String
                                           indentation)
            : document_(nullptr), indentation_(std::move(indentation)),
              addChildValues_(), indented_(false) {}

    void StyledStreamWriter::write(OStream& out, const Value& root) {
        document_ = &out;
        addChildValues_ = false;
        indentString_.clear();
        indented_ = true;
        writeCommentBeforeValue(root);
        if (!indented_)
            writeIndent();
        indented_ = true;
        writeValue(root);
        writeCommentAfterValueOnSameLine(root);
        *document_ << "\n";
        document_ = nullptr; // Forget the stream, for safety.
    }

    void StyledStreamWriter::writeValue(const Value& value) {
        switch (value.type()) {
            case nullValue:
                pushValue("null");
                break;
            case intValue:
                pushValue(valueToString(value.asLargestInt()));
                break;
            case uintValue:
                pushValue(valueToString(value.asLargestUInt()));
                break;
            case realValue:
                pushValue(valueToString(value.asDouble()));
                break;
            case stringValue: {
                // Is NULL possible for value.string_? No.
                char const* str;
                char const* end;
                bool ok = value.getString(&str, &end);
                if (ok)
                    pushValue(valueToQuotedStringN(str, static_cast<size_t>(end - str)));
                else
                    pushValue("");
                break;
            }
            case booleanValue:
                pushValue(valueToString(value.asBool()));
                break;
            case arrayValue:
                writeArrayValue(value);
                break;
            case objectValue: {
                Value::Members members(value.getMemberNames());
                if (members.empty())
                    pushValue("{}");
                else {
                    writeWithIndent("{");
                    indent();
                    auto it = members.begin();
                    for (;;) {
                        const String& name = *it;
                        const Value& childValue = value[name];
                        writeCommentBeforeValue(childValue);
                        writeWithIndent(valueToQuotedString(name.c_str()));
                        *document_ << " : ";
                        writeValue(childValue);
                        if (++it == members.end()) {
                            writeCommentAfterValueOnSameLine(childValue);
                            break;
                        }
                        *document_ << ",";
                        writeCommentAfterValueOnSameLine(childValue);
                    }
                    unindent();
                    writeWithIndent("}");
                }
            }
                break;
        }
    }

    void StyledStreamWriter::writeArrayValue(const Value& value) {
        unsigned size = value.size();
        if (size == 0)
            pushValue("[]");
        else {
            bool isArrayMultiLine = isMultilineArray(value);
            if (isArrayMultiLine) {
                writeWithIndent("[");
                indent();
                bool hasChildValue = !childValues_.empty();
                unsigned index = 0;
                for (;;) {
                    const Value& childValue = value[index];
                    writeCommentBeforeValue(childValue);
                    if (hasChildValue)
                        writeWithIndent(childValues_[index]);
                    else {
                        if (!indented_)
                            writeIndent();
                        indented_ = true;
                        writeValue(childValue);
                        indented_ = false;
                    }
                    if (++index == size) {
                        writeCommentAfterValueOnSameLine(childValue);
                        break;
                    }
                    *document_ << ",";
                    writeCommentAfterValueOnSameLine(childValue);
                }
                unindent();
                writeWithIndent("]");
            } else // output on a single line
            {
                assert(childValues_.size() == size);
                *document_ << "[ ";
                for (unsigned index = 0; index < size; ++index) {
                    if (index > 0)
                        *document_ << ", ";
                    *document_ << childValues_[index];
                }
                *document_ << " ]";
            }
        }
    }

    bool StyledStreamWriter::isMultilineArray(const Value& value) {
        ArrayIndex const size = value.size();
        bool isMultiLine = size * 3 >= rightMargin_;
        childValues_.clear();
        for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
            const Value& childValue = value[index];
            isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
                           !childValue.empty());
        }
        if (!isMultiLine) // check if line length > max line length
        {
            childValues_.reserve(size);
            addChildValues_ = true;
            ArrayIndex lineLength = 4 + (size - 1) * 2; // '[ ' + ', '*n + ' ]'
            for (ArrayIndex index = 0; index < size; ++index) {
                if (hasCommentForValue(value[index])) {
                    isMultiLine = true;
                }
                writeValue(value[index]);
                lineLength += static_cast<ArrayIndex>(childValues_[index].length());
            }
            addChildValues_ = false;
            isMultiLine = isMultiLine || lineLength >= rightMargin_;
        }
        return isMultiLine;
    }

    void StyledStreamWriter::pushValue(const String& value) {
        if (addChildValues_)
            childValues_.push_back(value);
        else
            *document_ << value;
    }

    void StyledStreamWriter::writeIndent() {
        // blep intended this to look at the so-far-written string
        // to determine whether we are already indented, but
        // with a stream we cannot do that. So we rely on some saved state.
        // The caller checks indented_.
        *document_ << '\n' << indentString_;
    }

    void StyledStreamWriter::writeWithIndent(const String& value) {
        if (!indented_)
            writeIndent();
        *document_ << value;
        indented_ = false;
    }

    void StyledStreamWriter::indent() { indentString_ += indentation_; }

    void StyledStreamWriter::unindent() {
        assert(indentString_.size() >= indentation_.size());
        indentString_.resize(indentString_.size() - indentation_.size());
    }

    void StyledStreamWriter::writeCommentBeforeValue(const Value& root) {
        if (!root.hasComment(commentBefore))
            return;

        if (!indented_)
            writeIndent();
        const String& comment = root.getComment(commentBefore);
        String::const_iterator iter = comment.begin();
        while (iter != comment.end()) {
            *document_ << *iter;
            if (*iter == '\n' && ((iter + 1) != comment.end() && *(iter + 1) == '/'))
                // writeIndent();  // would include newline
                *document_ << indentString_;
            ++iter;
        }
        indented_ = false;
    }

    void StyledStreamWriter::writeCommentAfterValueOnSameLine(const Value& root) {
        if (root.hasComment(commentAfterOnSameLine))
            *document_ << ' ' << root.getComment(commentAfterOnSameLine);

        if (root.hasComment(commentAfter)) {
            writeIndent();
            *document_ << root.getComment(commentAfter);
        }
        indented_ = false;
    }

    bool StyledStreamWriter::hasCommentForValue(const Value& value) {
        return value.hasComment(commentBefore) ||
               value.hasComment(commentAfterOnSameLine) ||
               value.hasComment(commentAfter);
    }

//////////////////////////
// BuiltStyledStreamWriter

/// Scoped enums are not available until C++11.
    struct CommentStyle {
        /// Decide whether to write comments.
        enum Enum {
            None, ///< Drop all comments.
            Most, ///< Recover odd behavior of previous versions (not implemented yet).
            All   ///< Keep all comments.
        };
    };

    struct BuiltStyledStreamWriter : public StreamWriter {
        BuiltStyledStreamWriter(String indentation, CommentStyle::Enum cs,
                                String colonSymbol, String nullSymbol,
                                String endingLineFeedSymbol, bool useSpecialFloats,
                                bool emitUTF8, unsigned int precision,
                                PrecisionType precisionType);

        int write(Value const& root, OStream* sout) override;

    private:
        void writeValue(Value const& value);

        void writeArrayValue(Value const& value);

        bool isMultilineArray(Value const& value);

        void pushValue(String const& value);

        void writeIndent();

        void writeWithIndent(String const& value);

        void indent();

        void unindent();

        void writeCommentBeforeValue(Value const& root);

        void writeCommentAfterValueOnSameLine(Value const& root);

        static bool hasCommentForValue(const Value& value);

        using ChildValues = std::vector<String>;

        ChildValues childValues_;
        String indentString_;
        unsigned int rightMargin_;
        String indentation_;
        CommentStyle::Enum cs_;
        String colonSymbol_;
        String nullSymbol_;
        String endingLineFeedSymbol_;
        bool addChildValues_: 1;
        bool indented_: 1;
        bool useSpecialFloats_: 1;
        bool emitUTF8_: 1;
        unsigned int precision_;
        PrecisionType precisionType_;
    };

    BuiltStyledStreamWriter::BuiltStyledStreamWriter(
            String
            indentation, CommentStyle::Enum
            cs, String
            colonSymbol,
            String
            nullSymbol, String
            endingLineFeedSymbol, bool
            useSpecialFloats,
            bool
            emitUTF8, unsigned int
            precision, PrecisionType
            precisionType)
            : rightMargin_(74), indentation_(std::move(indentation)), cs_(cs),
              colonSymbol_(std::move(colonSymbol)), nullSymbol_(std::move(nullSymbol)),
              endingLineFeedSymbol_(std::move(endingLineFeedSymbol)),
              addChildValues_(false), indented_(false),
              useSpecialFloats_(useSpecialFloats), emitUTF8_(emitUTF8),
              precision_(precision), precisionType_(precisionType) {}

    int BuiltStyledStreamWriter::write(Value const& root, OStream* sout) {
        sout_ = sout;
        addChildValues_ = false;
        indented_ = true;
        indentString_.clear();
        writeCommentBeforeValue(root);
        if (!indented_)
            writeIndent();
        indented_ = true;
        writeValue(root);
        writeCommentAfterValueOnSameLine(root);
        *sout_ << endingLineFeedSymbol_;
        sout_ = nullptr;
        return 0;
    }

    void BuiltStyledStreamWriter::writeValue(Value const& value) {
        switch (value.type()) {
            case nullValue:
                pushValue(nullSymbol_);
                break;
            case intValue:
                pushValue(valueToString(value.asLargestInt()));
                break;
            case uintValue:
                pushValue(valueToString(value.asLargestUInt()));
                break;
            case realValue:
                pushValue(valueToString(value.asDouble(), useSpecialFloats_, precision_,
                                        precisionType_));
                break;
            case stringValue: {
                // Is NULL is possible for value.string_? No.
                char const* str;
                char const* end;
                bool ok = value.getString(&str, &end);
                if (ok)
                    pushValue(valueToQuotedStringN(str, static_cast<size_t>(end - str), emitUTF8_));
                else
                    pushValue("");
                break;
            }
            case booleanValue:
                pushValue(valueToString(value.asBool()));
                break;
            case arrayValue:
                writeArrayValue(value);
                break;
            case objectValue: {
                Value::Members members(value.getMemberNames());
                if (members.empty())
                    pushValue("{}");
                else {
                    writeWithIndent("{");
                    indent();
                    auto it = members.begin();
                    for (;;) {
                        String const& name = *it;
                        Value const& childValue = value[name];
                        writeCommentBeforeValue(childValue);
                        writeWithIndent(valueToQuotedStringN(name.data(), name.length(), emitUTF8_));
                        *sout_ << colonSymbol_;
                        writeValue(childValue);
                        if (++it == members.end()) {
                            writeCommentAfterValueOnSameLine(childValue);
                            break;
                        }
                        *sout_ << ",";
                        writeCommentAfterValueOnSameLine(childValue);
                    }
                    unindent();
                    writeWithIndent("}");
                }
            }
                break;
        }
    }

    void BuiltStyledStreamWriter::writeArrayValue(Value const& value) {
        unsigned size = value.size();
        if (size == 0)
            pushValue("[]");
        else {
            bool isMultiLine = (cs_ == CommentStyle::All) || isMultilineArray(value);
            if (isMultiLine) {
                writeWithIndent("[");
                indent();
                bool hasChildValue = !childValues_.empty();
                unsigned index = 0;
                for (;;) {
                    Value const& childValue = value[index];
                    writeCommentBeforeValue(childValue);
                    if (hasChildValue)
                        writeWithIndent(childValues_[index]);
                    else {
                        if (!indented_)
                            writeIndent();
                        indented_ = true;
                        writeValue(childValue);
                        indented_ = false;
                    }
                    if (++index == size) {
                        writeCommentAfterValueOnSameLine(childValue);
                        break;
                    }
                    *sout_ << ",";
                    writeCommentAfterValueOnSameLine(childValue);
                }
                unindent();
                writeWithIndent("]");
            } else // output on a single line
            {
                assert(childValues_.size() == size);
                *sout_ << "[";
                if (!indentation_.empty())
                    *sout_ << " ";
                for (unsigned index = 0; index < size; ++index) {
                    if (index > 0)
                        *sout_ << ((!indentation_.empty()) ? ", " : ",");
                    *sout_ << childValues_[index];
                }
                if (!indentation_.empty())
                    *sout_ << " ";
                *sout_ << "]";
            }
        }
    }

    bool BuiltStyledStreamWriter::isMultilineArray(Value const& value) {
        ArrayIndex const size = value.size();
        bool isMultiLine = size * 3 >= rightMargin_;
        childValues_.clear();
        for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
            Value const& childValue = value[index];
            isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
                           !childValue.empty());
        }
        if (!isMultiLine) // check if line length > max line length
        {
            childValues_.reserve(size);
            addChildValues_ = true;
            ArrayIndex lineLength = 4 + (size - 1) * 2; // '[ ' + ', '*n + ' ]'
            for (ArrayIndex index = 0; index < size; ++index) {
                if (hasCommentForValue(value[index])) {
                    isMultiLine = true;
                }
                writeValue(value[index]);
                lineLength += static_cast<ArrayIndex>(childValues_[index].length());
            }
            addChildValues_ = false;
            isMultiLine = isMultiLine || lineLength >= rightMargin_;
        }
        return isMultiLine;
    }

    void BuiltStyledStreamWriter::pushValue(String const& value) {
        if (addChildValues_)
            childValues_.push_back(value);
        else
            *sout_ << value;
    }

    void BuiltStyledStreamWriter::writeIndent() {
        // blep intended this to look at the so-far-written string
        // to determine whether we are already indented, but
        // with a stream we cannot do that. So we rely on some saved state.
        // The caller checks indented_.

        if (!indentation_.empty()) {
            // In this case, drop newlines too.
            *sout_ << '\n' << indentString_;
        }
    }

    void BuiltStyledStreamWriter::writeWithIndent(String const& value) {
        if (!indented_)
            writeIndent();
        *sout_ << value;
        indented_ = false;
    }

    void BuiltStyledStreamWriter::indent() { indentString_ += indentation_; }

    void BuiltStyledStreamWriter::unindent() {
        assert(indentString_.size() >= indentation_.size());
        indentString_.resize(indentString_.size() - indentation_.size());
    }

    void BuiltStyledStreamWriter::writeCommentBeforeValue(Value const& root) {
        if (cs_ == CommentStyle::None)
            return;
        if (!root.hasComment(commentBefore))
            return;

        if (!indented_)
            writeIndent();
        const String& comment = root.getComment(commentBefore);
        String::const_iterator iter = comment.begin();
        while (iter != comment.end()) {
            *sout_ << *iter;
            if (*iter == '\n' && ((iter + 1) != comment.end() && *(iter + 1) == '/'))
                // writeIndent();  // would write extra newline
                *sout_ << indentString_;
            ++iter;
        }
        indented_ = false;
    }

    void BuiltStyledStreamWriter::writeCommentAfterValueOnSameLine(
            Value const& root) {
        if (cs_ == CommentStyle::None)
            return;
        if (root.hasComment(commentAfterOnSameLine))
            *sout_ << " " + root.getComment(commentAfterOnSameLine);

        if (root.hasComment(commentAfter)) {
            writeIndent();
            *sout_ << root.getComment(commentAfter);
        }
    }

// static
    bool BuiltStyledStreamWriter::hasCommentForValue(const Value& value) {
        return value.hasComment(commentBefore) ||
               value.hasComment(commentAfterOnSameLine) ||
               value.hasComment(commentAfter);
    }

///////////////
// StreamWriter

    StreamWriter::StreamWriter() : sout_(nullptr) {}

    StreamWriter::~StreamWriter() =
    default;

    StreamWriter::Factory::~Factory() =
    default;

    StreamWriterBuilder::StreamWriterBuilder() { setDefaults(&settings_); }

    StreamWriterBuilder::~StreamWriterBuilder() =
    default;

    StreamWriter* StreamWriterBuilder::newStreamWriter() const {
        const String indentation = settings_["indentation"].asString();
        const String cs_str = settings_["commentStyle"].asString();
        const String pt_str = settings_["precisionType"].asString();
        const bool eyc = settings_["enableYAMLCompatibility"].asBool();
        const bool dnp = settings_["dropNullPlaceholders"].asBool();
        const bool usf = settings_["useSpecialFloats"].asBool();
        const bool emitUTF8 = settings_["emitUTF8"].asBool();
        unsigned int pre = settings_["precision"].asUInt();
        CommentStyle::Enum cs;
        if (cs_str == "All") {
            cs = CommentStyle::All;
        } else if (cs_str == "None") {
            cs = CommentStyle::None;
        } else {
            throwRuntimeError("commentStyle must be 'All' or 'None'");
        }
        PrecisionType precisionType(significantDigits);
        if (pt_str == "significant") {
            precisionType = PrecisionType::significantDigits;
        } else if (pt_str == "decimal") {
            precisionType = PrecisionType::decimalPlaces;
        } else {
            throwRuntimeError("precisionType must be 'significant' or 'decimal'");
        }
        String colonSymbol = " : ";
        if (eyc) {
            colonSymbol = ": ";
        } else if (indentation.empty()) {
            colonSymbol = ":";
        }
        String nullSymbol = "null";
        if (dnp) {
            nullSymbol.clear();
        }
        if (pre > 17)
            pre = 17;
        String endingLineFeedSymbol;
        return new BuiltStyledStreamWriter(indentation, cs, colonSymbol, nullSymbol,
                                           endingLineFeedSymbol, usf, emitUTF8, pre,
                                           precisionType);
    }

    bool StreamWriterBuilder::validate(Json::Value* invalid) const {
        static const auto& valid_keys = *new std::set<String>{
                "indentation",
                "commentStyle",
                "enableYAMLCompatibility",
                "dropNullPlaceholders",
                "useSpecialFloats",
                "emitUTF8",
                "precision",
                "precisionType",
        };
        for (auto si = settings_.begin(); si != settings_.end(); ++si) {
            auto key = si.name();
            if (valid_keys.count(key))
                continue;
            if (invalid)
                (*invalid)[key] = *si;
            else
                return false;
        }
        return invalid == NULL || invalid->empty();
    }

    Value& StreamWriterBuilder::operator[](const String& key) {
        return settings_[key];
    }

// static
    void StreamWriterBuilder::setDefaults(Json::Value* settings) {
        //! [StreamWriterBuilderDefaults]
        (*settings)["commentStyle"] = "All";
        (*settings)["indentation"] = "\t";
        (*settings)["enableYAMLCompatibility"] = false;
        (*settings)["dropNullPlaceholders"] = false;
        (*settings)["useSpecialFloats"] = false;
        (*settings)["emitUTF8"] = false;
        (*settings)["precision"] = 17;
        (*settings)["precisionType"] = "significant";
        //! [StreamWriterBuilderDefaults]
    }

    String writeString(StreamWriter::Factory const& factory, Value const& root) {
        OStringStream sout;
        StreamWriterPtr const writer(factory.newStreamWriter());
        writer->write(root, &sout);
        return sout.str();
    }

    OStream& operator<<(OStream& sout, Value const& root) {
        StreamWriterBuilder builder;
        StreamWriterPtr const writer(builder.newStreamWriter());
        writer->write(root, &sout);
        return sout;
    }

} // namespace Json
